Waterproof blasting explosive assembly



Qrwem Ms w. R. FARREN ET AL WATERPROOF BLASTING EXPLOSIVE ASSEMBLY IFiled Aug. 26, 1933 WM F.JW%MMf- Dec. 10, 1935.

Patented Dec. 10, 1935 UNITED STATES f pal 123,784

PATENT OFFICE WATERPROOF BLAsTmG nxrno srvn ASSEMBLY William R. Farrenand Joseph Smith, Jr, a.

maqlla, Pa., assignors to Atlas Powder Com- D y, W ware ilmington, Del.,a corporation of Dcla- 1 Application August 2c, 1933,. Serial No.686,990

22 Claims. (Cl. roe-s) water-resistance of the explosive compositionsused, rather than upon the water-resisting quality of the shell orenvelope, in which the explo- 15 sive is encased. It is for this reasonthat the more costly and higher water-resistant types of explosives, asfor example the blasting gelatins and gelatinized dynamites, have beenalmost invariably employed for blasting under wet con- 20 ditions. Thishas resulted in unduly high. blasting costs, due not only to therelatively high cost of such type of explosives, but also to the factthat they are often less suitable in their-action for yielding the mostdesirable blasting results,

25 as compared with the less water-resistant types of explosives, whichmight otherwise be employed.

All previous attempts and proposals toward the production of suitableand practical water-proof 30 shells, so far as we are aware, have fallenshort of the mark because of either too great a cost or some other weakfeature that could'not be economically and practically overcome.

We are aware of such previous proposals as, 35 for example,hermetically-sealed containers of such materials as metal, rubber,rubberized cloth, waxed paper, paper-board, etc. all of which are eithertoo costly or otherwise objectionable, for example, having insuiiicientflexibility (too 40 rigid) or insuflicient bursting and/or tearingstrength to withstand the usual handling stresses involved with blastingoperations; and especially where deep bore-holes and high waterpressures are experienced. Further, we are aware 45 that various skincoatings have been heretofore proposed for use in conjunction withconventional or other types of blasting explosive cartridges, as forexample waxes, plastics, lacquers, tars, etc. All of these have thecommon de- 5 feet, however, of being too diflicult to apply so as toobtain always a completely water-proof envelope, on account of the factthat all require a period of time to set, dry or cool, during which timethe coating is sufliciently soft to permit 55 the formation of pores bythe passage of air therethrough; such passage being induced by thedifferential between the internal and external pressures of thecartridge, which usually exists and always is, present when the skincoating is applied at a temperature different from that of thesurrounding atmosphere. A further defect that is common to most types ofwaxes, tars and plastics for this purpose is their tendency to beeither'too brittle or else too sticky, soft and weak for proper handlingand it) good results within the temperature ranges.involved duringmanufacture, storage and. use.

In accordance with our present invention, we have discovered a type ofwater-resisting shell for blasting explosive assemblies which appreachesthe ideal, in that it obviates both the economic and technicaldisadvantages of the various water-proof blasting explosive assembliesheretofore known or used, as exemplified by those recited above; besidespermitting the practical use of the less costly and less water-resistingtypes of explosives and explwive compositions,

' such as black powder, non-gelatin'ized dynamites,

ammonium nitrate explosives, etc., even under severely wet conditionsand under considerable heads of water.

Our novel explosive cartridge assembly .comprises a charge of explosivecontained in a shell or envelope, the wall of which is both flexible andextensible (i. -e. capable of being easily bent, folded and enlarged inarea by stress) as well as water and moisture repellent; both in itsoriginal and its deformed (bent, folded or enlarged) state and whichenvelope comprises a preformed sheet of inherently extensible material.By this we mean a sheet of material which, before being incorporated inthe explosive cartridge, is stretchable under tension. An explosivecartridge of this novel type, which has beendeveloped and perfectedthrough extensive experi- 40 menting and thought, has the outstandingadvantage of being capable of conforming. itself within the confines ofa bore-hole, without breaking, bursting or tearing with consequententrance of water. For example, we have found that the water-proofedwrinkled or craped material as for 5 example, paper, cloth, etc. Thesaid material is also preferably craped so that it may be extended orstretched in more than one direction. The water-proofing may beaccomplished in any suitable manner, but preferably so that it willminimize the reduction in flexibility and extensibility of the crapedmaterial, as, for example, by impregnating, laminating or coating thematerial with a suitable flexible and extensible waterproofing mediumaslatex, tar, rubber, lacquer, asphaltic composition, wax, etc.

It may be observed that a straight rubber envelope may fall within thescope of the above definition, in that it may be both flexible andextensible. Rubber envelopes for explosives, however, have thedisadvantages, as compared with our novel type of easing comprising amaterial of the type of craped paper or fabric, of being much morecostly, of being more subject to time-deterioration and of having toomuch elasticity. Elasticity is objectionable in the magnitudeexperienced with an ordinary rubber film ofsufficient weight to beusable as a suitable casing for blasting explosives, because thisproperty tends to retard the conforming ability of a cartridge in thebore-hole. As soon as an elastic casing of this type is stretched, bentor extended, it is put immediately under tension and the greater thedeformation the greater the tension. This makes such a cartridge moredifficult to be charged into non-uniform and ragged bore-holes anddecreases the ease with which the cartridge can be made to "spread so asto completely fill the bore hole as, for example, where the highestpossible charging density is desired. We accordingly specify that thematerial used for the shell body or casing of our novel water-proofblasting explosive assembly be essentially non-elastic, in addition tobeing flexible and extensible. Thisc ombinationo f properties definesthe material as being capable of being deformed by bending, folding,stretching, etc., with but slight tendency to go back to its originalform and size, subsequent to such deformation. By craped, as used in theaccompanying claims, we mean a preformed sheet of material notnecessarily extensible in its composition but which has been renderedextensible.

by being provided with a multiplicity of wrinkles or fine corrugations,usually extending in many directions.

One example of a particularly desirable embodiment of our inventionconsists of a charge of blasting explosive contained in a shell bodyconsisting of two layers or lamina of craped paper cemented together bymeans of a substantially water-impervious internal layer or lamina ofasphaltic composition. The outer lamina of craped paper is preferablycoated and/or impregnated with a protective material as wax or lacquer,in order to render it more resistant to the softening and disintegratingaction of the water and moisture, with which it may come in contact, aswell as to add materially to the waterresisting property of the shellbody material as a whole without undue reduction in the extensibility ofthe same. The seems, as well as the openings through which the explosiveis charged into the shell, are preferably sealed by means of awater-resisting, flexible adhesive medium as latex, rubber cement,lacquer, asphaltic composition, tar, etc. In view of the usualsensitivity of blasting explosives to heat, it is quite preferable,however, to employ an adhesive medium for the final closure of theloaded explosive cartridge, that may be applied to effect a water-proofseal at or near atmospheric temperatures. For this reason, we prefer theuse of such adhesive as latex, rubber cement, lacquers, etc., which maybe ap- 5 plied in this more desirable manner.

The figures shown in the accompanying drawing are merely explanatory andare not intended to be limiting, since there are many other ways inwhich the invention may be applied. 10

Figure 1 is a view, partly in side elevation and partly in section, ofan explosive assembly package embodying the principles of the invention.

Figure 2 is an enlarged sectional view through the material of which thecontainer is formed; 15 and Figure 3 is a view, partly in side elevationand partly in section, of a type of large scale container in whichsticks of dynamite, for example, may be stored, shipped, or otherwisecontained.

Referring now to the drawing, 5 designates the inner lamina, 6 the outerlamina, ancLLthe interposed lamina of a water-proofing composition ofany of the material's herein defined. The laminae 5 and 6 consists ofcraped material, pref- 25 erably craped paper, though we contemplate theuse of any suitable crape or otherwise extensible and substantiallynon-elastic material; the advantages of which have already beenexplained.

A sheet of material consisting of the lamina, 30 shown in Fig. 2, issuitably shaped to form a container, such for example as thatillustrated in Fig. 1 where the sheet of material is first brought totubular form. This may be accomplished by providing the material with alongitudinal seam 35 along its abutting edges, cemented with a suitablewater-proofing composition of the class defined herein.

There are numberless ways in which the ends of the receptacle may besealed, and we contem- 40 plate employing any of the well known bagfolds employed in the manufacture of paper habs. One way in which acontainer may be sealed at the bottom is illustrated in the accompanyingdrawing wherein the material is merely bent over upon 45 itself;suitable adhesive being applied, at 8, and, if desired, again, at' 9, toseal first the abutting faces to each other and then to seal the turnedover edges at the point 9. Another way of sealing an end of a tubularstructure of this sort 50 is to gather the material of the end of .thetube, as indicated at H), applying a wire bagtie, or other suitablebinding element 1 l, thereto, and dip the gathered end into a body ofwaterproof sealing composition such as tar, asphaltic 55 composition,latex, rubber cement or lacquer. Where the bag-tie is used, its eye I!provides means for the attachment of a lowering cord by which theexplosive assembly may be lowered into a bore hole. We also contemplatethe draw- 60 ing of the gathered end l0, by means of bag-tie orequivalent element about a rubber plug, in order to seal the package andin the manner described in the patent to Farren, No. 1,890,726, datedDecember 13, 1932. 05

In Figure 3, we have indicated that laminated extensible material of thecharacter described may be employed in the formation of containers ofconsiderable size. In said figure, a container l3, formed of thelaminated extensible sheet herein 70 described, serves as a receptaclefor a plurality of sticks of dynamite I 4. This illustration is givenmerely to emphasize the fact that our described material is of utilityin relations other than as .l

the casings of single cartridges. Material of this 76 nature constitutescheap and efllcient means for the shipment of explosives into humidcountries, or under other adverse weather conditions, with the assurancethat such shipments will be found in first class condition upon arrivalas far as any deterioration from moisture is concerned. 1

It will be understood that the above example is not limiting and thatwecontemplate a vast number of variations thereof, all of which fairlycome within the scope of this specification. may, for example, employone or a multiplicity of craped paper or fabric laminae in conjunctionwith one or more laminae or coatings of a suitable water-proofingsubstance. We may employ various media for fastening and water-proofingthe seams, as described above, and we may employ various means ofclosing the ends of the shell body as well as various attachments, ifdesired, to make for easier handling and loading of the cartridges.

It should be further understood that we are 'of conventional types, withor without individual shell coverings, coatings, etc.

Further, relative to the auxiliary water-proofing treatment of thecasing of the assembly, we may choose to not treat it at all, or we mayapply the protective medium at. the time the material is manufactured orany time prior to or subsequent to the loading of the assembly withblasting explosive; as for example, by coating, spraying, dipping, etc.This said treatment may also be applied to one or more or all of thecraped lamina, as requirements dictate. By the term extensible materialas used in the appended claims, I mean a material having inherentextensibility, as for example the craped material described, and I donot mean to include ordinary plain paper which is not inherentlyextensible of itself even though it may be folded into plaits to make anextensible structure.

Having described our invention, what we claim is:

1. A blasting explosive assembly comprising a charge of blastingexplosive and about the said explosive charge a container, substantiallyof a flexible and extensible material consisting of two laminae ofcraped paper cemented together by means of a water-resisting innerlamina of asphaltic composition.

2. A blasting explosive assembly as in claim 1, further characterized bythe seams and openings of the said container being sealed and fastenedby means of at least one flexible and water-resisting adhesive substanceof the group consisting of tar, asphaltic composition, latex, rubbercement and lacquer.

3. A blasting explosive assembly comprising a body of explosive materialand a container for said explosive material, the walls of said containerconsisting of at least one layer of craped material that is flexible andinherently extensible but substantially non-elastic, and at least' onelayer of water-proofing composition on the layer of craped material.

4. A blasting explosive assembly as in claim 1, characterized by atleast one of the creped paper lamina: being treated with an auxiliarywater and moisture-repelling medium.

- 5. A blasting explosive assembly as inclaim 1, characterized by atleast one of the craped paper laminae being treated with an auxiliarywater 5 and moisture-repelling medium taken from the characterized bythe outer lamina of craped 10 paper being treated with molten parafllnwax.

7. A blasting'cartridge assembly comprising a blasting explosive chargecontained in a sheath consisting of a flexible, extensible,water-resisting and essentially non-elastic material that sub.-stantially comprises a preformed-sheet the 'seams and openings of whichare sealed and fastened shut by means of a flexible water-resistingadhesive substance, and at least one end of which is held in a gatheredfold by means of a wire 20 bag-tie. b

8. A blasting explosive assembly comprising a water-proof shell that isflexible, extensible in more than one direction but non-elastic, and achargeof blasting explosive therein, said shell 5 consisting of twolaminae of crepe papercemented together bymeans of a. water resistingelastic: composition.

9. A blasting explosive assembly as in claim 8 characterized by theseams'and openings of the 30 said shell being sealed and fastened bymeans of at least one flexible water resisting adhesive substance of thegroup consisting of tar, asphaltic composition, latex, rubber, cementand lacquer.

10. A blasting explosive assembly comprising a water-proof shell and acharge of blasting explosive therein substantially completely fillingthe interior of said shell and of a nature sufliciently freely moving tobe flowable in all di- 40 rections, the walls of said shellcomprising-at least one layer of crane material that is flexible andextensible in substantially all directions but substantiallynon-elastic.

11? A blasting explosive assembly comprising a 45 water-proof shell anda charge of blasting explosive therein substantially completely fllhngthe interior of said shell, the walls of said shell comprising at leastone layer of .crepe material that is flexible and extensible in morethan one 50 direction but substantially non-elastic, and a layer ofwaterproofing composition on the layer of crepe material.

12. A blasting explosive assembly comprising a body of blastingexplosive and a container about 55 the said explosive; the saidcontainer being char-. acterized as made of a moisture-resisting ma--terial that is essentially flexible, extensible. (in more than onedirection), non-elastic and at least a substantial part of whichconsists of a 0 preformed sheet of inherently extensible material.

13. A blasting explosive assembly comprising a' body of blastingexplosive and a container about the said explosive; the said containerbe- 65 ing characterized as made of a moisture-resisting material thatis essentially flexible. extensible, non-elastic and comprises at leastone preformed lamina of flexible and inherently extensible, crapedmaterial.

14. A blasting explosive'assembly as recited i claim 13, wherein thesaid preformed lamina consists of flexible and extensible craped paper.

15. A blasting explosive assembly comprising a body of blastingexplosive and a container 75 about the said explosive; the saidcontainer being characterized as made of a moisture-resisting materialthat is essentially flexible, extensible, non-elastic and substantiallycomprises at least one lamina of extensible craped material and at leastone lamina of an extensible and flexible water-resisting material.

16. A blasting explosive assembly as recited in claim 12, furthercharacterized by the seams and openings of the said container beingsealed and fastened by means of a flexible and water-resisting adhesivesubstance.

17. A blasting explosive assembly as in claim 15 wherein the saidwater-resisting material is of the group consisting of tars, asphalticcompositions, latex, rubber cements and lacquers.

18. A blasting explosive assembly comprising a charge of blastingexplosive-and a water-proof shell container for the same consisting of asheet of relatively strong, tough material that is flexible, extensiblein substantially all directions, but is non-elastic, said sheet ofmaterial being coated with aflexible, water-resisting substance.

19. A blasting explosive assembly comprising a body of blastingexplosive and a container about the said explosive; the said containerbeing characterized as made of a moisture-resisting material that isessentially flexible, non-elastic,

and at least a substantial part of which consists of a preformed sheetof inherently-extensible material.

20. A blasting explosive assembly comprising a body of blastingexplosive and a container about the said explosive; the said containerbeing characterized as made of a moisture resisting material that isessentially flexible, extensible, nonelastic and at least a substantialpart of which consists of a. material which when in flat form presents asheet preformed to render it inherently extensible.

21. A blasting explosive assembly comprising a body of blastingexplosive and a container about the said explosive; the said containerbeing moisture resisting, flexible and non-elastic and comprising apreformed sheet of inherently extensible material and a layer offlexible, extensible, water-resisting material.

22. A blasting explosive assembly comprising a body of blastingexplosive and a container about the said explosive; the said containerbeing moisture resisting, flexible, and non-elastic and comprising alayer of flexible, extensible, water-resisting material between twopreformed sheets of inherently extensible material.

WILLIAM R. FARREN. JOSEPH SMITH, JR-

